2018 - 2019 USGS Lidar: Northern California Wildfire - QL1

Product: These lidar data are processed Classified LAS 1.4 files, formatted to individual 1000 m x 1000 m tiles; used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

Geographic Extent: 8 counties in California: Butte, Lassen, Marin, Plumas, Shasta, Sierra, Tehama, Yuba

Dataset Description: The Northern California - QL1 project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.3. The data were developed based on a horizontal projection/datum of NAD 1983 2011 Contiguous USA Albers, Meter and vertical datum of NAVD88 GEOID 12B, Meter. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to individual 1000 m x 1000 m tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1000 m x 1000 m schema. Continuous breaklines were produced in Esri file geodatabase format.

Ground Conditions: LiDAR was collected in summer, fall, and winter 2018 and winter, spring, and summer 2019, while no snow was on the ground and rivers were at or below normal levels. In order to post process the LiDAR data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Quantum Spatial, Inc. utilized a total of 387 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 678 independent accuracy checkpoints, 380 in Bare Earth and Urban landcovers (380 NVA points), 298 in Tall Weeds categories (298 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

The NOAA Office for Coastal Management (OCM) downloaded this data set in 4 blocks from this USGS site:

ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/

The blocks downloaded were:

USGS_LPC_CA_NoCAL_Wildfires_B5b_QL1_2018 Number of files: 1799

USGS_LPC_CA_NoCAL_Wildfires_CampFire_2018 Number of files: 768

USGS_LPC_CA_NoCAL_Wildfires_PlumasNF_B1_2018 Number of files: 4298

USGS_LPC_CA_NoCAL_Wildfires_PlumasNF_B2_2018 Number of files: 5081

These files were processed to the Data Access Viewer (DAV) and https. The total number of files downloaded and processed was 11,946.

Hydro breaklines are also available. These data are available for download at the link provided in the URL section of this metadata record. Please note that this product has not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM.

To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create intensity images, breaklines and raster DEMs. The purpose of these LiDAR data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 1 meter cell size. These raw LiDAR point cloud data were used to create classified LiDAR LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.

Contract No. G16PC00016, Task Order No. 140G0218F0251; CONTRACTOR: Quantum Spatial, Inc.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.3",

"ldrsens" : "Riegl VQ1560i",

"ldrmaxnr" : "unlimited",

"ldrnps" : "0.71",

"ldrdens" : "2.0",

"ldranps" : "0.48",

"ldradens" : "4.34",

"ldrfltht" : "2000",

"ldrfltsp" : "160",

"ldrscana" : "29",

"ldrscanr" : "46",

"ldrpulsr" : "100",

"ldrpulsd" : "3",

"ldrpulsw" : "0.36",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.18",

"ldrswatw" : "2217.0",

"ldrswato" : "55",

"ldrgeoid" : "GEOID 12B",

"ldrcrs" : "NAD 1983 2011 Contiguous USA Albers, Meter"

},

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.3",

"ldrsens" : "Leica ALS70",

"ldrmaxnr" : "4",

"ldrnps" : "0.71",

"ldrdens" : "2.0",

"ldranps" : "0.6",

"ldradens" : "2.78",

"ldrfltht" : "2200",

"ldrfltsp" : "140",

"ldrscana" : "15",

"ldrscanr" : "46",

"ldrpulsr" : "245",

"ldrpulsd" : "4",

"ldrpulsw" : "0.48",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1179.0",

"ldrswato" : "30",

"ldrgeoid" : "GEOID 12B",

"ldrcrs" : "NAD 1983 2011 Contiguous USA Albers, Meter"

},

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.3",

"ldrsens" : "Leica ALS80",

"ldrmaxnr" : "unlimited",

"ldrnps" : "0.71",

"ldrdens" : "2.0",

"ldranps" : "0.6",

"ldradens" : "2.78",

"ldrfltht" : "2300",

"ldrfltsp" : "140",

"ldrscana" : "14",

"ldrscanr" : "60",

"ldrpulsr" : "240",

"ldrpulsd" : "2.5",

"ldrpulsw" : "0.51",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.22",

"ldrswatw" : "1147.0",

"ldrswato" : "30",

"ldrgeoid" : "GEOID 12B",

"ldrcrs" : "NAD 1983 2011 Contiguous USA Albers, Meter"

},

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Specification v1.3",

"ldrsens" : "Riegl VQ1560i",

"ldrmaxnr" : "unlimited",

"ldrnps" : "0.71",

"ldrdens" : "2.0",

"ldranps" : "0.6",

"ldradens" : "2.78",

"ldrfltht" : "2300",

"ldrfltsp" : "140",

"ldrscana" : "30",

"ldrscanr" : "165",

"ldrpulsr" : "800",

"ldrpulsd" : "3",

"ldrpulsw" : "0.41",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.18",

"ldrswatw" : "2656.0",

"ldrswato" : "30",

"ldrgeoid" : "GEOID 12B",

"ldrcrs" : "NAD 1983 2011 Contiguous USA Albers, Meter"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0.087",

"rawnvan" : "374",

"clsnva" : "0.086",

"clsnvan" : "380",

"clsvva" : "0.27",

"clsvvan" : "298"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld bit.",

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit.",

"lasintr" : "16",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare-Earth Ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "In-land Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge Decks"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignored Ground"

},

"lasclass" : {

"clascode" : "21",

"clasitem" : "Snow (where identifiable)"

},

"lasclass" : {

"clascode" : "22",

"clasitem" : "Temporal Exclusion (if applicable)"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Inc., USGS, NOAA, the Office for Coastal Management or its partners,

Data is available online for bulk and custom downloads.

None

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

MicroStation Version 8; TerraScan Version 18; TerraModeler Version 18; GeoCue Version 2017.1.14.1; Esri ArcGIS 10.3; Global Mapper 19; Leica Cloud Pro 1.2.4, RiProcess 1.8.5; Windows 10 Operating System

\\point_cloud\tilecls\*.las

The specifications require that only nonvegetated vertical accuracy (NVA) be computed for raw LiDAR data swath files. The vertical accuracy was tested with 374 independent survey points located in open terrain. These check points were not used in the calibration or post processing of the LiDAR data. The survey check points were distributed throughout the project area.

Tested 0.087 meters NVA at a 95% confidence level using 374 independent survey points located in open terrain. The survey check points were distributed throughout the project area. The 374 independent check points were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified LiDAR surface were measured for the x,y location of each checkpoint. Elevations interpolated from the LiDAR surface were then compared to the elevation values of the surveyed control points. The root mean square error vertical (RMSEz) was computed to be 0.044 meters. AccuracyZ has been tested to meet 19.0 cm NVA at 95-percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using American Society of Photogrammetry and Remote Sensing (ASPRS) Guidelines.

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and the data pass Non-Vegetated Vertical Accuracy specifications.

Data cover the entire area specified for this project.

Data is backed up to tape and to cloud storage.